1. Field of the Invention
This invention relates generally to closure arrangements, and more particularly it relates to a closure arrangement including a composite lid composed of a molded plastic rim and a flexible film central panel adapted to be secured to a container body having a rim which can be hermetically sealed to the lid.
2. Background Art
A search of the records of the U.S. Patent Office directed at the subject matter of this application discovered the following U.S. Pat. Nos.:
______________________________________ 3,428,208 4,154,360 5,125,529 3,892,351 4,442,971 5,160,767 3,934,749 4,542,029 5,167,339 4,044,941 4,605,142 5,328,045 4,094,460 4,856,674 5,439,132 4,141,463 5,069,355 ______________________________________
A review of the above patents determined that none of the patents disclosed or claimed a closure arrangement with a one-piece resealable lid as taught within the present application.
The present invention is drawn to a lid or cover for a cup of the type where it snaps over a flange of the cup. The cup is retained in place by a clip or undercut. Typically, such cover which includes a paperboard or plastic central panel is snapped over a membrane or foil seal and the package is opened in two steps. The first is removal of the cap and the second being removal by peeling off of the membrane. In this arrangement, the lid is then available to reclose the package.
Membranes for sealing cups of this sort are typically accomplished by one of several ways. This first of these is the utilization of a flexible film applied off the roll to the top of the cup and heat-sealed onto the flange and then cut from a web. As an alternative, individual precut membranes are fed from stacks. These are typically aluminum foil and are textured to stiffen and are very expensive. Another approach is the utilization of membranes which are preinserted into caps and induction sealed to flanges. This system also requires foil and generally is limited to small screw cap enclosures. Membranes of the types applied above are typically sealed with conduction wherein a hot dye is applied under pressure until the membranes sealant is bonded to the cup flange. In another approach, the membranes are sealed by induction wherein an electrical field is induced in aluminum foil to generate the necessary heat for sealing.
In the arrangements outlined above, the heated dye must have direct contact to the sealing area and without any thick layers of material in the way, and by means of induction, heat can be induced deeply within the structure.